gnupic: Re: [gnupic] gputils development
Subject:
Re: [gnupic] gputils development
From:
David ####@####.####
Date:
25 May 2007 03:55:10 +0100
Message-Id: <20070524214920.543107b3@DEEPTHOUGHT.BARNET.net>
On Thu, 24 May 2007 17:43:34 -0700
Scott Dattalo ####@####.#### wrote:
> David Barnett wrote:
> > ...
>
> I can take some time to discuss strategy for gputils if you like.
Okay, you can change the subject if you think there are more pressing
topics to address, but here's what I've been thinking.
I don't know how much trouble porting the pcode system will be as
opposed to the actual optimizations, but it's not a good starting place
for someone who doesn't know what they're doing yet (e.g. me), because
it's a lot of changes before any results come out and hence a lot of
room for misunderstanding; it's probably a one-man job for the same
reason. I know it's been a while since you worked with gputils; if
you're not up to it anytime soon, I'll just need to buckle down and fix
some of the small bugs for the next few weeks or months until I
understand the system well. There aren't many candidates for the job...
If you remember the issues I brought up with indirect addressing and
side-effects before, I think it'd be good to figure out a rough plan how
to deal with those soon, because I'm not seeing anything. My concern is
the pcode needs some order to it to be useful, and computed gotos make
it hard to isolate the entry points on the basic blocks. You have to
backtrack from the computed goto to find the value of PCLATH and the
value loaded into PCL, and the entry points are important for
backtracking, so it seems like there's a circular dependency.
> > ...
>
> I don't have any input on the '$ label clash' bugfix since I'm not
> familiar with it.
If you don't remember, that was the thread with the subject "'pagesel
$' dup error", and also SDCC bug #1652040 and gputils bug #1652208. It
was a simple fix, but since gputils hasn't been under active
development in a while, it never got released. There are a few other
bugs regarding compatibility with MPLAB that we could maybe fix in CVS
before releasing and moving to SVN.
David Barnett
